Managing networks can largely be a matter of risk management and decision support. Network administrators want to minimize the risk of events such as equipment failure while, at the same time, maximize performance such as maintaining high bandwidth. These types of management tasks bring with them a number of types of data management problems. For example, for failures in the network, the types of questions that an administrator needs to ask depend upon the current context: such as how, where and when did the event occur. Oftentimes, when a given network device experiences a failure, the network device itself may not be able to notify an administrator or what went wrong, leaving the administrator with insufficient information to diagnose and correct the failure.